Connecting rod assemblage



March 16, 1948. ROSE- CONNECTING ROD ASSEMBLAGE Filed June 2, 1944 3mm 3Zaurence R056 Patented Mar. 16, 1948 UNITED STATES PATENT OFFICECONNECTING ROD ASSEIVIBLAGE Laurence Rose, Washington, D. 0.

Application June 2, 1944, Serial No. 538,463

Claims. 1

This invention relates to improvements in connecting rod assemblages,and more particularly to the formation of the assembly at thecrank-shaft end of the rod.

Connecting rods are generally employed for converting reciprocatingmotion into rotary motion, or vice versa, one end of the rod beingconnected to a piston and the other end to a crank of a crank-shaft; ifthe power is applied to the piston the conversion is to the rotatingmotionif the power is applied to the crank-shaft, the conversion is tothe reciprocating motion. In either case, the crank-shaft end of the rodtravels in a circular path the diameter of which is represented by twicethe distance between the crankshaft axis and the axis of the crank.

The most .common illustration of the service is the connecting rodinstallations used in internal combustion motors, the motors generallyoperating under Otto cycle principles, in which the cycle includes tworevolutions of the crankshaft and four strokes of the piston, eachpiston stroke presenting one-half revolution of the crank-shaft; one ofthe piston strokes is the power stroke (produced by the firing of thecharge), thus setting up the power drive as from the piston to thecrank-shaft; the succeeding three strokes of the piston (scavenging,intake, and compression) are provided by the rotation of thecrank-shaft, the latter becoming the drive for the connecting rod; dueto this condition, motors of this type generally have at least fourcylinders with their individual pistons and connecting rods, thecrank-shaft having a corresponding number of cranks, the arrangementthus providing for at least one power impulse to the crank shaft duringeach half revolution of the latter, the ofisetting of the cranks beingarranged-in connection with the timing mechanism-to provide for theproper timing.

These well-known conditions are being referred to to explain causes forcertain conditions that are present in connection with the operation ofeach of the connecting rods, and especially of the crank-shaft end ofsuch rods. Since these are spaced apart on the crank-shaft, each willtraverse its individual circular path, with the paths having a commonaxis. And since the paths are circular, each presents certain conditionswhich are also present (with a different timing) with each of theconnecting rods; hence, a disclosure as to one rod will suffice for all.These conditions will be understood from the following:

Assume the motor to have its cylinders above the crank-shaft, thushaving the pistons reciprocating vertically with the power stroke of apiston moving downwards; in practice, the timing is such that the chargeis fired at such time that the combustion of the charge begins justafter the piston has passed its upper dead center, with the axis of thecrank-shaft end of the connecting rod approximating a similar positionin the circular path. As the piston moves downward, its pressure isapplied on the crank of the crank-shaft through the connecting rod, andsince the crank-shaft rotates bodily in its axis, the crank will havethe travel of the crank pin axis conforming to the circular path, thiscrank pin axis representing the axis of the bearing insert in thecrank-shaft end of the connecting rod.

This travel of this end of the connecting rod and its bearing insert, intraversing the circular path produces a number of characteristicconditions which tend to set up stress conditions of considerablemagnitude-the stress magnitude value will depend upon the rotationalspeed of the motor. For instance, while the travel of the crank-shaftend of the connecting rod will be downwnard and laterally outward at thebeginning of the power stroke, this condition ends when the axis of suchends reaches the angular position-the horizontal diameter of the path;the axis continues downwardly after passing this point, but thedirection of the lateral component is changed from the previous outwarddirection to an inward direction, thus providing a reversal of thiscomponent; the axis continues its advance under the latter conditions,until the position of the vertical diameter is reached at which time theprevious downward component changes to an upward direction while theinward lateral component continues in the same direction to become alaterally outward component with respect to the vertical diameter; thischange remains active during the succeeding 90 travel (to the 270angular position) whereupon the lateral component is reversed to theinward direction with the upward component continuing as before; thisrelation of the components continues to the point which completestraversal of the path and provides a single revolution of thecrankshaft. While this detail analysis presents changes, it can beunderstood that in effect, the components continue in one direction whentraveling through the path on one side of a diameter (vertical orhorizontal) and in the reverse direction on the other side of suchdiameter, With this condition of reversal alternating as 3 between thediameters at midway points of the 180 angular travel.

These four points of reversal in direction during a revolution of thecrank-shaft present potential sources of stress development, due to thefact they present points where the normal tendency of the end zone ofthe connecting rod to continue its direction of travel under kineticconditions reaches anv endand begins travel-in. a different directionrelative to the axis of the crank pin; the effort of the rod end zone tocontinue in the same direction tends to draw the bearing insert intocloser relation to. the crank pin on the opposite side of the latter atthe instant of reversal. speed of the motor is increased, since thekinetic value also is increased; with a motor speed 'of 2000 R. P. M.8000 of such reversals per minutewould be present.

The condition is amplifiedas the weight of such end zone of theconnecting rod isincreased, due to the fact thatthe weight factorincrease tends.

to increase the momentum effectpresent in the inertia of motion that is.present, thus increas ing the value of the resistance tochangeirrdirecr. tionunder the inertia action. Obviously, therefore, the-lessthe weight of such end. zone of the connecting rod, the less becomes thevalue of the. stresses which may be set up. It may be noted. thatalleviation in the value of the stresses isdependent upon thepossibility of varying the weight factor, since the factor previouslydiscussed. is inherently present at. all times of operation of themotor.

However, the-conditions are-accentuated. by thefact that the end zone ofthe connecting rodmust be secured upon the crank pin of the cranlearm ofthe' crank-shaft, with both ends of thepin.

closed against endwise positioning of the rod. end-zone, a condition.which necessitatestheuse or a divided rod end zone in order to, permitpositioning of the'rod on the pin. In practice. the division line ismadeona line. normal to the length of'the connecting rod, this beingpreferred-,due to. the fact that during the traversal of the circularpath this line would extend, angular to-the.hori-. zontal diameter of.the path dueto theinclination of the connecting rod to'the vertical.dameter at the 90 and 270 angular positions on. the. path. thus assuringthat the breakin unitary continuity of the end-zone willbe somewhatremote from the positions of reversal at these points-the re.- versalsat the other points are remote from the break points to a maximum extentsince the connecting rod is in correspondence with: the. verticaldiameter at such times.

Under modern practice, the actual bearingsurface of the rod end zone onthe crank pin is provided by a thin shell of special alloy metal. ofvcircular contour and provided with side flanges. which overlie theopposite faces of the. rod end. zone, thus permitting renewal by simplesubstitution of one shell for another--the,. shells. are. known'asbearing inserts. Since such bearing iii-- sert encircles the crank pinit is necessary toiorinit sectional similar to the end zone, the-two,sec.-- time being accurately dimensioned to. fit the pin when inposition thereon; since the insert is not united to the connecting rod,bodily creeping of theinsert is possible,v so that the lineof meeting.of the insert sections-which correspondsqto a diameter of the insert-mayvary its position relative to the line of meeting of the rod end-zonesections; but this does not renderv the insert more vulnerable to theactions produced by the re- This effect increases: as"the;-:

versals above referred to, since, if the two meeting lines are in alinedposition, the insert meeting line will be remote from the points ofreversal similar to the line of the rod end zone-when out of alinernent,the insert will be protected by unitary portions of the rod end-zone.

This arrangement of the insert permits the rod to be made lighter inweight through selection of rod material, but; the reduction in ossibleweight is limited by the fact that the sections of the rod end zone mustbe secured together and with a strength suflicient to preventseparation; for instance, during the third stroke of the cycle--theintake stroke--the power is provided by the crank-shaft; thus placingthe power application upon the removable section of the connecting rodendzone, thus requiring a connecting means of sufficient: strength tonot only ensure the proper maintenance of the bearing insert in properoperation, but alsohto resist separation during this stroke.

In modern practice, such connection is provided by increasing thethickness of the rod within the end zone of the rod and forming a boredhousing thereon on, each side, the housing and its bore crossingthejunction line of the end zone-thus dividing. the housing. toplace thetwo sections of the housing asv respectively unitary with the sectionsofthe end, zones being connected; each section of the housing. is ofconsiderable length axially of the bore. with the. two portionsgenerally of similar length; the bore is designed to receive a bolt thehead. of which is above the upper section (and preferably arranged toprevent bolt rotation), the opposite end of the bolt being exposed belowthe lower section to. receive the nut, suitable means (such as radialkeris on the under face of the nut, and a cotter pin mounted in aselected kerf and extending through a diametrical opening in the bolt)being provided to retain the bolt in its-secured position, thisstructure beingsimil-ar onopposite sides of the end zone, Intermediatethe bottoms ofthe housings, the bottom of the end zone is formed with arib. to give strength to the lower section ofthe end zone of the; rod.

This: structure provides sufiicient strength to maintain theintegrity ofthe end zone against separation, whilepermitting ready assembly of therod endzone and bearing insert on the crank pin, thus making it possibleto substitute bearing insertswithout requiring expert assistance.However, it is a structure that adds materially to the weight of thiszoneof the connecting rod, as can be understood from the fact that thehousing must include a straight bore with the latter extending in a linethat is practically tangent to a circle; since the housing at. thedivision line must have a dimension sufficient to house the bolt outsideof the bearing openingwith this dimension as the smallest projectedportion of the housing and since all portions of the housing must be insecured relation to. the assembled circular. portion. of the end zone,the structure sets up-a weight factor of considerable amount, especiallysince smooth running requires that the weight distribution shouldapproach symmetrical conditions as closely as possible.

The. present invention has for its principal object a reduction in thisWeight factor Without affecting the strength or operating efiiciency ofthe connecting rod and also to permit ready substitution of bearinginserts. The reduction is provided bychanging the manner of connectingthe sections of the end zone of the rod. With the exception of thehousings and bolts, the connecting rod remains generally as before, thepresent invention substituting a difierent form of fastening means and achange in the form of the required body to receive the means, the changematerially reducing the weight of this zone of the rod. Since, at highspeeds, such reduction reduces the service eiiects set up by theconditions described above in detail, the invention will tend to reducewear development to provide longer life to the bearing inserts, andprovide for smoother operation of the assembly.

This latter can be understood somewhat by considering the generalcharacteristics of kinetic energy. The general condition is indicated byconsideration of the fact that the value of kinetic energy increaseswith the mass and with the square of the velocity mv (1mhence, anydecrease in the weight of the crankshaft end of the connecting rod(mass) reduces the value of the kinetic energy in accordance with theabove formula, in which 12 represents the velocity. Obviously, anymaterial reduction in weight, even if small, provides a considerablereduction in the angular momentum values which are present at theinstants of reversal in direction referred to above, especially underhigh speed operation, thus reducing the stress values at such time.

To these and other ends, therefore, the nature of which will be betterunderstood as the invention is hereinafter disclosed, said inventionconsists in the improved construction and combination of parts asdescribed hereinafter, illustrated in the accompanying drawings, andmore particularly pointed out in the appended claims.

In the accompanying drawings, in which similar reference charactersindicate similar parts in each of the views Figure 1 is a view in faceelevation of the crank-shaft end zone of a connecting rod showing theinvention applied thereto.

Figure 2 is a sectional View taken on line 2-2 of Figure 1.

Figure 3 is a sectional View taken on line 3-3 of Figure 1.

Figure 4 is a perspective view of one form of key employed in theinvention.

Figure 5 is a view in side elevation of another form of key which may beemployed.

The connecting rod, designated as i9, has the general characteristics ofthe general form of rods in practically universal use, no change beingmade in theform of the piston end of the rodthe reason for omitting thisportion in Figure lthe change being in the end-zone which cooperateswith the crank-shaft; likewise, the body portion ii intermediate theend-zones re mains unchanged. Similarly, the crank-shaft end-zone,indicated at I2, is enlarged diametrically to provide the opening !3 forthe crank pin (not shown). the thickness dimensions being sinol"? tothose in general use; and the end-zone has the usual dividing lineextending on a diameter of the end-zone and the opening, with thediameter extending normal to the length axis of ti: rod, to thereforeprovide the lower end i2a as a removable section to thereby permit therod to be secured on the crank pin, the complemental portion of the bodyportion of the zoneindicated at I la, being formed unitary with the bodyH. In addition, opening [3 contains the usual divided bearing insert l4.

One of the changes made from the usual form is that of extending theexternal rib throughout the periphery of the zone with the exception ofthat portion included in the body portion of the rod within the zone,the rib, indicated at I5, being carried by both portions Ila and We andtherefore divided on the diameter heretofore referred to.

Another change is in connection with the faces of the end-zone, Underthe usual practice, this face, in the assembly, is not only completelyannular, but completely circular externally, the housing heretoforereferred to being depressed with respect to the plane of the face. Inthe present embodiment this is preferably changed to provide anenlargement l6 at opposite sides, with each enlargement symmetricallydisposed relative to the division line referred to, so that eachenlargement is divided by such division line, the preferred form placingthe face of the enlargement as in the plane of the usual face andextending to and formed integral with rib I5; however, it will beunderstood that the face of the enlargement may be varied as todimensions, if

desired, such change being deemed within the spirit and scope of theinvention.

The peripheral contour of the enlargement may be of desired form, but ispreferably curved and preferably extends outward to the outer dimensionof the rib. This is preferred since it tends to provide a streamlineeifect to the zone while traversing the circular path traveled by thecrank pinthe rod becomes angular to the vertical when the pin reachesthe horizontal diameter of the circle and reaches the vertical when thepin is on the vertical diameter of the circle-conditions which provide aswing of the enlargement about the axis of the pin first in onedirection from the horizontal diameter position, and return, and. thenin the opposite direction and return, the horizontal diameter positionbeing present when the rod is on the vertical diameter; under high speedoperation, the curvature of the enlargement offers the least resistanceand thus provides for less turbulent air conditions in the path oftravel of such end-zone.

The chordal thickness of the enlargement at its base is sufiicient toassure ample support for the securing means, presently described, toassure non-separation of the lower end of the connecting rod from thebody by the stresses produced by the assembly in operation; since theenlargement is preferably arranged symmetrical to the horizontaldiameter the latter bisects the chordal thickness. In practice, the lineof the chordal thickness will, however, preferably have a length lessthan the inner diameter of the bearing insert, so that the volume ofmetal within the enlargement is considerably less than that found in thehousing of the prior art form discussed above; while the rib structurereduces the amount of difference, this change in form provides a verymaterial reduction in the weight of this end zone of the connecting rod,a reduction value which is enhanced by the change in the securing meanswhich, in the present invention, is in the form of a key the weight ofwhich is-considerably less than the weight of the bolt and nut structurefor which it is being substituted.

The securing means is in the form of a complemental key and slotpositioned in each of the two enlargements, and of a somewhat particularconfiguration. These configurations may be anemone varied- -two forms ofkeys. are disclosed to illus trate possibilities, and it isto beunderstood that the forms shown are representative and may be stillfurther varied to meet individual conditions and the preferences of theuser, such changes being: considered within the present invention.

The key configuration of both of the forms shown presents, in verticalcross-section, a verti-cal web portion Ila (and Ila) and a pair ofhorizontally extending heads Nb (and Nb) at the top and bottom; of theweb, thus presenting somewhat the apperance of the letter H; thevertical height of the web is such as to provide I a distance factorsuchthat when the web is mounted symmetrical to. the horizontal diameterof the end zone, a material amount of metal of the enlargement of bothportions of the end zone will be located between'the heads Ill) andlib). The key I! shown in Figure 4, has the length of the web- Ha asapproximating the axial length of the end zone, as represented by thelength of the enlargement in the same direction; in this form it ispreferred that the length does not ex ceed this distance, and may beless than such distance, but must be suflicient to provide the strengthneeded to resist separation of the parts of the end zone. In this form,the length of the heads l'lb is such as to extend beyond the ends of theweb, as shown. In addition, the web, in side elevation presents thevertical distance between the heads as progressively increasing from oneend to the other of the web; the variations arepreferably equal withrespect to the two heads, the web thus presenting the appearance of aface diverging from one end to the other, the inner faces of the headsthus presenting characteristics of wallsof a slight tapered formation.

The. key shown in Figure has its vertical cross-section similar to thatshown in Figure 4, but therelative length dimensions are reversed ascompared with Figure 4the heads I'll) have the length of the webinFigure 4, while they web He has the length of the heads ill) in Figure4; in addition, the extensions of the web are each preferablyrovidedwith slots l'l'c extending inwardly from the free ends, thus, in effect,dividing the extensions into a pairof tongues l'id for a purposepresently referred to-the extensions of the heads in Figure 4 aredesigned to serve as tongues for a similar purpose. As in Figure 4, theweb has the-progressively increasing width toward one end, thusproducing the slight tapered formation of the key formation as in Figurel.

The cross-section of the slot formation of an enlargement iscomplemental to the cross-section of the key, with the web zoneextending across the horizontal diameter which provides the divisionline of the end zone of the rod, while the head portions of the slotextend in the slightly angular directions presented by the heads of thekey formation, so that the slot formation will present a substantialreplica of the various crosssections of the key formation when the bodyportion H and the crankeshaftend zone l2 are in their working positionsof complete contact. In other words, the top and bottom faces of thehead portion of the slot are parallel, but the faces extend in adirection that is inclined away from and toward the division line of theend zone, with the inclination extending from one face to the other ofthe rod end-zone, while the side faces of the head slots are paralleland spaced to provide a working fit for the corresponding faces of theheads of the key.

Inpractice, the dimensions of the slots of the end zoneconfiguratlonswithin each of the enlargement portions ofthe crank-shaftend zone of the. connecting rod. correspond generally with those of thebody of the. key when the two parts of the end zone are drawn togetheron the line of division of such parts; the slots are arrangedsymmetrical relative. to such division line, so that the widths of theweb. portion of the key will be found symmetrically positioned withinthe slots with the web extending across such division line. In otherwords, with the keys properly positioned, the end zone assembly becomesthe equivalent of a unitary structure so far as operative effect isconcerned.

Since,:to produce this efiect, the slots must conform to theslighttapered width configuration of the key, it is apparent that inassembling the connecting rod and crank pin, the key must be inserted inits slot by movement in an endwise direction of the key, with the largerweb end introduced into the slot end which receives the smaller width ofweb. To permit key introduction, therefore, the two parts of the rod endzone-after the bearing insert: has been positioned on the crank pinareretained separated a distance suiiicient to place the head portions ofthe slot at the key entrance end in alinement with the head portions ofthe larger end of the key, whereupon the key is introduced and shiftedalong the slot. And since the key remains unchanged in dimensions, andthe head portions of the slot also remain unchanged in dimensions, thechange in dimensions due to key movement is temporarily provided by thespacing of the end zone parts on the line of division of the parts-theinner faces of the key heads, during the shiftin action, will contactthe complemental faces of the slots with the effect of drawing the twoparts of the rod end zone closer together, this continuing until the twoparts of the end zone are drawn tightly together, due to the effect ofthe tapered form of the web.

The wedge-like values are comparatively small (possibly .001 to .002inch for each head) so that the spacing of the end-zone members for thepurpose of the key may amount to .002 to .004 of an inchit being obviousthat both keys will be inserted into the entrance to the slots beforebeginning advance of the keys in the slots. To decrease this initialspacing, the outer faces of the key heads may be slightly chamfered atthe end which is to be introduced-as at lle'thus decreasing thethickness of the entrance end face of the key heads-after entering, thespacing of the rod end zone parts will be controlled by the key; in theFigure 4 form the chamfering will provide little effect in theappearance of the completed assembly, while in the Figure 5 form thesmall chamfering values-have no material efiect on the strength of thejoint, and the small opening provided by the chamfer will have littleeffect in the appearance and then only on one of the opposite faces oftheend zone occupied by a key. Obviously, the taper formations of theslots may be arranged to expand from the same face of the rod end-zone,or may extend from opposite faces of such zone; the former is preferredsince both keys are then inserted on the same face of the end zone.

After the keys have been advanced to the desired position, at which timethe extensions (the ends of the heads in the Figure 4 form, and theextensions lid in the Figure 5 form) project beyond the faces of theassembled rod end-zone, these extensions are then bent over into contactwith end-zone faces, as indicated in Figure 3, for instance. This locksthe key in position; this may be done only at one end of the key-theWider end-but it is preferred to do this at both ends to preventmovement of the key due to the inherent vibratory effects produced bythe travel of the end zone assembly in the circular path. The Figure 3presentation is that of the Figure 4 form of key, in which case theextensions become located outwardly beyond the slot top and bottomcontours; in the Figure 5 form, in which the extensions are carried bythe web, the extensions are moved outwardly in the lateraldirection-while a single extension might be utilized (and iscontemplated within the invention), the dual form shown is preferred,this permitting the two extension portions to be shifted in oppositedirections, thus tending to maintain the key against any possibility ofrocking, being similar in this respect to the bending of both heads inthe Figure 4 form.

The description above as to drawing the two parts of the rod end-zonetightly together, presents the preferred method of utilizing theinvention. While this would seemingly limit the amount of wear possibleon the bearing insert,

the fact that the insert is of a special alloy designed to withstandrapid wear, together with the fact that adequate lubrication is alwayspresent, tends to produce comparatively long life to the insert; this isespecially true because of the fact that with such arrangement thebearing insert can provide its internal opening as of truly cylindricaltype at the time of forming the insert, and thus provide a perfectcomplemental relation with the crank pin when the connecting rod isinstalled-the lateral flanges .at the sides of the inert will normallymaintain this relationship; the same conditions would be present wherethe two halves of the insert are slightly less than 180 of angularlength, thus leaving these halves slightly spaced apart.

However, it is apparent that if it is desired to utilize self-conforminginserts-inserts which can slightly change their form through resiliencyand without producing material change in wear conditions, the two partsof the rod end-zone may be retained slightly spaced apart initially,making possible the taking up of wear by later driving the keys inwardlya greater distance and thereby draw the parts into closer relationship.Where this method is employed, the taper values could be slightlyincreased so that the drawing action could be provided with acomparatively short range of key-driving action. While this method maybe employed-and is considered within the inventionits use is lesspreferred, due to the need for the resilient insert characteristic andthe possibility of unequal wear conditions being set up.

When substitution of a bearing insert is necessary, the extensions atthe larger ends of the keys may be brought back to their initialpositions by the use of a suitable tool, after which the key is drivenout in a reverse direction from which it was introduced, thus tending toseparate the rod-end zone parts through the taper action thusfacilitating the separation of the parts; in such case carefulmanipulation of the extensions will permit re-use of the key; or theextensions may be cut off, leaving the key free to be driven out andthus limit the life of the key to the single use.

As will be understood, the change in construction provided by thepresent invention, as compared with the present commercial practiceabove described, presents a very material advantage in favor of thepresent invention, due to the very material decrease in the weight ofthe rod endzone assembly. While the usual rib zone is extended in thepresent invention, the enlargement area is small as compared with thehousing of the commercial form. In addition, the weight of the key isgreatly reduced as compared with the weight of the bolt, nut and cotterpin utilized in the commercial form. Since this weight reduction ispresent on opposite edges of the endzone assembly, the totality ofreduction assumes considerable value, a condition which is of positiveadvantage when the rod'is in service with the end-zone traversing thecylindrical path. The weight reduction reduces the kinetic energy valueswhich must be overcome at the instants of reversal of directionexplained above, thus tending to reduce the stresses inherently presentas well as vibratory effects; obviously, wear tendencies will tend to bereduced because of these conditions.

While I have herein shown and described several Ways for carrying theinvention into effect, it is apparent that changes or modificationstherein may be found desirable or essential in meeting the exigencies ofuse and the individual desires of the user; I therefore reserve theright to mak any and all such changes or modifications as may be founddesirable or essential, insofar as the same may fall Within the spiritand scope of the invention as expressed in the accompanying claims, whenbroadly construed.

What is claimed is:

1. In connecting rod assemblies, wherein one end zone of the rod isformed with a bearing opening and is operatively mounted on a crank pinor analogous structure extending within such opening and operative totravel with the pin in a circular path, wherein the assemblage includesan insertable bearing insert mounted on the pin within the bearingopening, and wherein such rod end zone and the bearing insert are eachof sectional formation to permit mounting of the assemblage on the pinand the insertion and removal of the bearing insert Within theassemblage at will, the combination with such assemblage, of means foroperatively securing the end zone sections together about the pinand'the interposed bearing insert, said means including an insertablekey formation having its lengthwise direction extending in generalparallelism with the axis of the bearing insert, and a complemental slotformation in such end zone, said key and slot formations beingsymmetrically disposed relative to the opposing faces of adjacentsections of the end zone to operatively connect such sections andprevent separation thereof during service, a cross-section of said keyforma tion including a web portion with a pair of spaced head portionsintegrally united thereto at opposite edges of the web portion and withthe head portions projecting laterally beyond a side face of the webportion, the slot formation presenting the web-receiving portion of theslot as crossing the division line between the rod endzone sections atan angle to such line, said Web portion of the key having the depth ofits face of gradually-increasing dimension from end to end of its activesection-holding length to thereby provide a dimension of taperingcharacteristic between the opposing inner faces of thelaterallyprojecting zones of the head portions, whereby key advanceafter key insertion in the slot form'ation will cause the adjacentsections to be drawntoward each otheig at least one of said key portionshaving an extension projecting at the advance en'd of the key andadapted to be bent up'onan adjacent exposed face of the end zone tothereby anchor the inserted key against undesired releasing movement ofthe key due to vibratory effects,

2. An asse'mblage as in claim 1 characterized in that the rod 'end zoneis divided on a diameter of the bearingopening extending normal tothedirection of length ofthe connecting rod to thereby provide atwo-section rod end zone, a second key formationand slot formation being'providedatthe diametrically opposite side of the rod end zone. 7 7

3. An fassemblage 'as in claim 1 characterized in that the rod endjzoneis divided on a diameter of the bearing opening extending normal to thedirection 'Qf fIBII gth of the connecting rod to thereby provide a twosection rod end zone, a second ke'yform'ation'and slot formation beingprovidedat the diametrically opposite side of the rod end zone, thekeyand slot formations at both poiptsnbeing substantial duplicates,

4 Anassgmblage as, in claim 1 characterized in that the end zon'e'of therod presents the usual reinforcing rib characteristic in extended formwith the adjacent section's combinedly providing additional enlargedface reinforcements integral with the rib"formation and dimensioned toinclude theislot'forma'tionwith the heads of the slotvspaced from theperipheral contour of the reinforcements'and from the division linebetween the sections. I

5. An assemblage as in claim 1 characterized in that the end zone of therod presents the usual reinforcing. rib characteristic in extended formwith the adjacent sections combinedly providing additional enlarged facereinforcements integralwith the rib formation and dimensioned to includethe. slot formation with the heads of the slot space d,,from theperipheral contour of the reinforcement and from the division linebetween the sections, such contour being curved arcuately to presentv asubstantial reinforcing formation at, the section securing point oflimited weight characteristic with the contour tendingrto providestreamline action to the end zone duringservice. to V V 6. An assemblage'as in claim 1 characterized in thatth'e key includes an anchoringextension at its r'ear end in addition to the extension at the'advahfceend, to thereby rigidly anchor the key against all vibratory action.

7*. assemblage as in claim 1 characterized in that each head portion ofthe key carries an anchoring extension. I

8. An assemblage as in claim 1 characterized in that the web portion ofthe key carries an anchoring extension.

9. An assemblage as in claim 1 characterized in that the web portion ofthe key carries an anchoring extension with the extension divided topermit bending of one of the divisions in a direction opposite the otherdivision to thereby stabilize the key.

10. An assemblage as in claim 1 characterized in that the outer face ofeach head of the key has its leading edge 'cham'fered or rounded tothereby permit ready entrance of the key within the slot and aid incontrolling the positions of the adjacent rod end sections beingconnected by the key during key-entering operations.

LAURENCE ROSE.

REFERENCES CITED Thefollowing references are of record in the fileofthis patent:

UNITED STATES PATENTS Number 7 Name Date 137,227 M'arJ25, 1873 234,370 fHdi heS -Q'NOV. 9, 1880 236,099 Huber et a1. -1 Oct. '2, 1883 "401,585'Pollar'd Apr. 16, 1889 466,622 Oren'stein Ja'n. 5, 1992 714,955Shartle' De'c."2, 1902 1;00'1,11s Langlands Oct. 31, 1911 1,158,436Bowen Nov. 2, 1915 1,219,382 Dunlap Mar. 13,1917 1,469,527 Oud'erkirkOct. 2,1923 1,525,982 Clark et al. 1 Feb. 10, 1925 1,721,561 Jensen Ju1y23, 1929 1134 10 Wells -Nov. 5, 1929 2,134,765 "Putnam nov. 1,19382,146,493 'Wintzer 'Feb. 7, 1939 FOREIGN PATENTS Number Country Date413,272 'Great Britain- July '9, 1934 615,243 Germany July 1,1935

